For electric cars and hybrid cars, a battery module including a plurality of cells that are connected in alignment is used, and the battery module is provided with a means for detecting the voltages of the cells (see JP 2011-91003A below). Generally, the voltage detection means has a structure in which a harness that binds together voltage detection lines connected to the electrodes of the cells is connected to a control unit via a connector.
For the battery module of this kind as well, there is a need to integrate the module as a whole, including the voltage detection means, in a compact manner. As an example, a battery module having a structure has been proposed in which a control unit is mounted on the upper face of the battery module, and on the other hand, a harness is pulled out from the control unit, and a device-side connector connected to a terminal end of the harness is disposed on a predetermined mounting surface such as a side surface of the battery module, and a wire-side connector connected to a terminal end of the harness of the voltage detection line is fitted to the device-side connector on the mounting surface.
Meanwhile, depending on the type of the battery module, an assembly or reinforcement frame may be disposed so as to extend from an end edge of the mounting surface, for example. In that case, it may not be possible to secure a fitting space for the wire-side connector, on the mounting surface of the device. To deal with this problem, it is conceivable to remove the device-side connector, then fit it to the mating wire-side connector in a state in which the device-side connector is separated from the mounting surface, and thereafter fit the device-side connector to the mounting surface again. However, inevitably, the operation of fitting and mounting the connector, including storing an excess length of the harness, takes time and effort.
The technique disclosed herein has been completed in light of the above-described situation, and it is an object thereof to make the connector mounting portion compact while keeping the connector mounting operation simple.